Morphological, Histochemical, and Proteomic Analysis of the Effects of Fluoride and Amoxicillin, with Calcium and Vitamin D Supplementation, on Dental Enamel Formation.

Ameloblasts are the cells exclusively responsible for enamel formation. Although this process is genetically regulated, external factors such as fluoride and amoxicillin can interfere with enamel development. Some studies suggest that calcium supplementation may reduce the deleterious effects of fluoride on enamel. The aim of this study was to evaluate whether fluoride and/or amoxicillin impair ameloblast viability and enamel formation, and whether calcium and vitamin D supplementation reduce the potential damage caused by these substances to dental enamel. Although calcium and vitamin D administration increased the superficial resistance of enamel to acid challenge, hydroxyapatite crystals were disorganized in the inner enamel of the experimental groups. Ameloblasts exhibited apoptotic bodies and positive staining for caspase-3 and TUNEL. KLK4 levels were reduced within ameloblasts from fluoride-treated groups but the abundance increased in the enamel matrix. In addition, the abundance of AMBN, AMTN, and ODAM in the matrix was reduced. No statistical differences in abundance of amelogenins was observed. These findings indicate that fluoride exposure, exacerbated by concomitant amoxicillin use, compromises multiple axes of amelogenesis, resulting in a structurally disorganized and functionally weakened enamel.